Karsten Plamann, Danièle Fournier, Benoît C. Forget,
Laboratoire d'Instrumentation, Université Pierre & Marie Curie
ESPCI, 10 rue Vauquelin, 75231 Paris cedex 05, FRANCE
A. Claude Boccara
Laboratoire d'Optique Physique, ESPCI, 10 rue Vauquelin, 75231 Paris cedex 05, FRANCE
abstract
It is generally known that the microstructure of polycristalline CVD diamond samples has a
strong impact on their thermal properties. Despite the fact that nowadays layers can be
deposited with macroscopic conductivities and diffusivities rivalling those of type II natural diamond, the samples are highly thermally inhomogeneous and sometimes show local values differing up to two orders of magnitude.
To examine thee phenomena more closely, we present a microscopic photothermal measuring method for the local thermal diffusivity.
We demonstrate the feasability of diffusivity measurements at a sample sufrace of ca. 20 x 20 µm.
We show results obtained on a reference sample of known diffusivity and presents measurements of the diffusivity inside a monocrystal at the growth side of a CVD diamond layer.